28 J. BRONTE GATENBY 



the chromosome, Golgi element, and niitochonch-ium, is capable 

 of growth and binary or multiple fission. 



Buchner, in his paper on the secondary nuclei of parasitic 

 Hymenoptera, among the other conclusions, comes to the two 

 following: accessory nuclei are to be traced back at the 

 beginning, as naked chromatin (sic) granules lying in the 

 cytoplasm. From these granules develop enchylema, nuclear 

 membrane, and linin network, while the granule itself becomes 

 the nucleolus of the accessory nucleus. Buchner has used 

 safranin and light green and iron haematoxylin as stains ; he 

 labours under the delusion that what stains in a basic dye 

 must necessarily be chromatin. He states that the chromatin 

 granule which induces the formation of karyolymph, linin 

 network, and nuclear membrane, later becomes a 'nucleolus'. 

 Buchner figures the oocyte of Bombus and Myrmecina showing 

 the nucleoli of the head nucleus as red granules (safranin) 

 and a more or less faint chromatin (?) network green (' licht- 

 griin'). The accessory nucleus also shows a red nucleolus and 

 a green network. Buchner and others have concluded that 

 the red-staining substance of the head nucleus, which becomes 

 extruded through the nuclear membrane, is chromatin. As 

 I have mentioned before I do not believe that one should lay 

 too much weight on the staining tests (and Buchner has not 

 tried several of the stains I should like to have seen used), 

 but the points which must be emphasized are, firstly, that it 

 is proven that the nucleolus of many hymenopterous insects 

 does fragment and partly pass into the cytoplasm ; and 

 secondly, that these fragments do form secondary nuclei, 

 exactly similar in certain species, to the head or principal 

 nucleus. Call the red-staining body inside the head nucleus 

 what one may, plastin or chromatin, plasmosome or karyosome, 

 it is a fact that fragments of it can give rise to secondary 

 nuclei. 



There is some temptation to use the facts which have recently 

 been described in parasitic Hymenoptera, and in this paper, 

 with reference to the behaviom* of nucleoh, as support for 

 a ' binuclearity ' hypothesis of some kind. In a recent paper 



